Dashcam - good camera

Could someone with a dashcam setup please tell me which camera they have and where they mounted it? I want to do someone similar to what has been described in multiple posts, but I havent found a post so far that describes why kind of camera to buy. I mainly want to use it in case of accidents.

A few months ago a lady backed up into me in the middle of the road to avoid another accident and luckily she told the truth that she hit me, but she could have easily lied and said I rear-ended her in which case I would have been screwed without any evidence.